My sorcerer/wizard Vaeron used his hawk familiar, Snatch, pretty often as a scout, a Light-bearer, and support in combat. Snatch has battled other scouting familiars in the air and even gargoyles, though to little effect in the latter case (though at least he proved kind of distracting to them, while Vaeron and the other PCs attacked from range). Never terribly effective or anything, but handy and used a lot.
In the Oriental Adventures campaign I ran, the numerous hengeyokai sorcereresses in the party often had their familiars around and active in searching, scouting, and chatting. Of course, being hengeyokai, they spent a lot of time in their own tiny-animal alternate forms. It was wierd how many of those kinda PCs we had in that campaign.

I think the players of the hengeyokai roleplayed their familiars' actions as much as their PCs'. I don't recall all the familiars' names off the top of my head, but they were all named. I've never really gamed with anyone who didn't at least name their familiars.
In that same campaign, the vanara shaman's tiger animal companion was a vicious combatant, and often a significant presence in the group. Of course he was the only one who could talk to it, and keep the tiger from springing on anyone, like the small familiars of the sorcereresses.... I don't recall if the tiger had a name or not, or if the vanara shaman just preferred not to label it with a made-up name.
In other campaigns I've run, the familiars and animal companions have seen some decent use and 'screen time'. In the main Rhunaria campaign, Karil's familiar is a tressym (winged blue-grey cat from the FRCS book), introduced in the campaign as a corporeal spirit creature that came to him when he performed the familiar-summoning ritual. Carillus, as he named it, has been a frequent advisor to Karil on matters of the spirit realm and occasionally a source of amusement. Carillus has helped out a bit in combat once in a while, but mostly serves as a scout and advisor. It's been active in some manner or another in most of the game sessions since Karil summoned it. The rogue/sorceress named Mouse acquried a parrot familiar at one point (I considered it a raven-equivalent familiar), who mostly speaks up on occasion for comic relief or an odd comment or two, but hasn't been very important. Sniklis the kobold druid was fond of his dire bat animal companion, which served as his flying mount and support in battle (though he was careful to avoid Nesskill getting hurt too much).